Spark-plug.



W. L. EDISON.

SPARK PLUG.

APPLICATION FILE JUNE s, 1908.

1,081,728. Patented Dec. 16, 1913. 15 76 18 I WIL AM L. nnrson, or ORANGE, new JERSEY.

SPARK-I'LUG.

specification of Letters Patent.

Patented Dec. 16, 1913.

Application file 1 1 98.- 1 N 437, 5-

To all whomz't may concern:

Be it known that I, WILLIAM L. En soN, a citizen of the United States of Amerlca, residing at Orange, in the county of Essex and State of New Jersey, have invented certain new and useful 1m, rovements in Spark- Plug-s, of which the fol owing is a specification, reference being had therein to the accompanying drawing.

This invention relates to a spark-plug of the jump-spark class for internal combustion engines, my object being to extend the conductors through the core of porcelain, r other insulat ng mate ial, In such a man.- nor that the core wil n t eweak ned as much as usual, and will be much less l able t reak,

With this and other objects in v18W my nvention consists in the peculiarities heremafter more fully described and claimed Referring to the accompanying draw/lugs,

T Figurelrepresents a longitudinal elevatlon of my complete spark plug. Fig. 2, a similar view part-1y in section. Fig. 3, a longitudinal section. Fig. 4, an end view, Fig. 5, an end view of the opposite or outer end of the plug, with the cap removed, and Fig.

' 6, adiagraimnatic View.

Each of the two electrical conductors, together with the external connectors and the spark gaps, are constructed exactly al ke, and a description of one will apply to both.

The reference numeral 1 indicates an ordis nary spark plug bushing provided with taporing threads adapted to screw into the cylinder head of a gas engine.

2 is an el ngated core composed, p ferably, of porcelain, although it might be i made of mica or glass, This core has a central circular enlargement 3 adapted to enter the bushing and to be clamped between a shoulder 4 and the end of a locking sleeve 5 screwed into the bushing and surrounding the core. Suitable washers 6 are interposed between the parts to make a gas-tight joint a nd pre -entreakag un er pressur t th s eeve.

7 represents a short alining pin fixed to Two separate and independent electrical circuits 9 and 9 Fig. 6, extend longitudinally through the core 2 of the plug, each consisting of a conductor 10, such as an ordinary wire of any proper material, tapered down and secured in any suitable manner to an exceedingly fine gage sparking terminal 9. The conductor 10 may be either integral or fused with the reduced terminal. The purpose of thus reducing the terminal down to the thread-like gage is to choke or intensify the current at the spark gap, and thereby produce a stronger spark which will be more potential in igniting the gases in the cylinder of an internal combustion englue, and particularly so when the gas is under extremely high compression. Said terminal is, preferably, composed of platinum, or any other good conductor capable of resisting the disintegrating effects of intense heat, and its extreme outer end lies flush with the sparking or smaller end of thcplug, in contradistinctio-n to those spark gap terminals or points which project a short distance beyond the end of the plug. The conductor 10 extends longitudinally through the core of the plug in a slightly torsional or spiral line for the purpose of avoiding as much as possible the more weakening efiect of running these two conductors in straight parallel lines, for it is desirable to maintain as much strength as possible in the core, owing to its susceptibility to breakage from vibration. The upper end of each conductor 10 terminates in a head 11 whi h sits in the lower end of a longitudinal hole 12 in which is located a tubillar electrical conductor 13 connected with a latside, its outer end being provided with the usual binding screw 16.

AS, already stated, the inner or sparkin end of the core 2 is conical and the reduce I wire terminals 9 emerge from the opposite sides'of the inclined wall thereof at a point about half way between the apex and the base of the cone, thereby separating the two terminals sufliciently to bring them opposite or under tw inturned hook-shaped terminals or sparking points 17 and 17*. These ioo points are set in the ends of the bushing 1" in the old and well known manner, so that the current will jump from the terminals 9 to, the terminals 17 and 17 whenever the circuits are completed. It will be seen that this location of the two terminals 9 in relation to each other allows the outer end of the conical portion of the core 2 to come between the terminals and thereby assist in preventing the establishment of a short circuit. The fine wire terminals or electrodes 9 are baked in the porcelain in order to perfectly-insulate them as well as to more the free circulation of thegases during explosion to break up the accumulation of soot that might, otherwise collect to short circuit the spark gap.

18 represents a cap which fits over the top of the plug in order to give it a neat appearance and protect the connections.

Having thus described my invention, what I claim-as new and desire to secure by Letters Patent, is:

-1. In a spark plug, the combination of a non-conducting core having a conical sparking end and a pair of electrical conductors insulated from each other and passing longitudinally through the core, said conductors terminating flush with the conical surface of said sparking end on opposite sides of the apex of the cone, substantially as described. w

2. In a spark plug, the combination of a non-conducting core having a conical sparking end, a pair of conductors, insulated from each other, and passing longitudinally through the core, and a fine gage sparking terminal secured to the end of each conductor, said terminals terminating flush with the conical surface of said sparking end on opposite sides of the apex of the cone, substantially as described.

.3. In a'spark plug, the combination of a non-conducting core having a conical sparking end, a pair of conductors, insulated from each other, and passing longitudinally through the core, and a fine gage sparking terminal secured to the end of each connos-1,728

with the conical surface of said sparking end on opposite sides of the apex of the.

cone, and said terminals being baked in the core, a conducting bushing surrounding said core, and spark terminals carried by said bushing and cooperating with said first mentioned terminals to form -spark gaps, substantially as described.

4. In a spark plug, the combination of a non-conducting core having a conical sparking end' and a pair of electrical conductors insulated from each other and passing longitudinally through the core, said conductors terminating flush with the conical surface of said sparking end on opposite sides of the apex of the cone, a conduct: ingbushing surrounding said core, and a pair of sparking terminals carried by said bushing adapted to coiiperate with the terminals of the electrical conductors of the core toform a pair of spark gaps, said core and bushing being provided with cooperating means which upon the assembling of the core and bushing insures that said terminals will always be brought into the same relative and correct positions to form said spark gaps, substantially as described.

5. In a spark plug, the combination of a nonconducting core having a conical sparking end, a pair of conductors insulated from each other and passing longitudinally through the core, a fine gage sparking terminal secured to the end of each conductor, said terminals terminating flush with the conical surface of said sparking end on opposite sides of the apex of the cone, a conducting bushing surrounding the said core, and sparking terminals carried by said bushing and cooperating with said first mentioned terminals to form spark gaps, said core and bushing being provided with cooperating means which upon the assemblin of the core and bushing insures that sai terminals will always be brought into the same relative and'correct positions to form said spark gaps, substantially as describcdf In testimony whereof I ailix my signature in presence of two witnesses.

lVILLIAh I L. EDISON. lVit-nesses RrirsA G. DuBors,

C. B. Scrmonnnn.

flopiel of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

